Liquid phase desulfurizer, method for preparing and using the same and method for high temperature desulfurization

Abstract

This invention relates to the field of desulfurization technology, and discloses a liquid-phase desulfurizing agent, its preparation method, its application, and a high-temperature desulfurization method. The liquid-phase desulfurizing agent provided by this invention comprises: an ionic liquid, a metal chelate, and an aqueous solvent, wherein the metal element includes Fe. The liquid-phase desulfurizing agent provided by this invention has the advantages of high sulfur absorption, high desulfurization efficiency, and high-temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of desulfurization technology, specifically to a liquid-phase desulfurizing agent, its preparation method and application, and a high-temperature desulfurization method. Background Technology

[0002] Hydrogen sulfide is a toxic, harmful, and corrosive substance. It is produced during the in-situ conversion of crude oil into oil products, accompanied by an increase in temperature. Current oil and gas field desulfurization processes and agents are not suitable for the high-temperature production conditions of in-situ converted produced fluids. A series of operations, including cooling and separation, are required before desulfurization, resulting in a long process flow, large equipment investment, and high operating and maintenance costs. Therefore, there is a need to develop a highly efficient desulfurizing agent suitable for high-temperature conditions.

[0003] Currently, hydrogen sulfide removal technologies mainly include dry desulfurization and wet desulfurization. Dry desulfurization refers to a class of processes that use solid-phase desulfurizing agents to remove sulfur, mainly including the iron oxide method, activated carbon method, Claus method, and manganese ore desulfurization method. Dry desulfurization has disadvantages such as slow reaction rate, poor desulfurization performance for gases with high sulfur content, and poor recovery. Therefore, wet desulfurization processes are more widely used than dry desulfurization.

[0004] Wet desulfurization refers to a class of processes that use liquid-phase desulfurizing agents to remove sulfur, including wet absorption desulfurization and wet oxidative desulfurization. Wet absorption desulfurization refers to the absorption of hydrogen sulfide using liquid-phase absorbents, mainly including ionic liquid absorption and N-methylpyrrolidone methods. However, some liquid-phase absorbents, such as N-methylpyrrolidone, polyethylene glycol dimethyl ether, and cold butanol, not only absorb hydrogen sulfide but also heavy hydrocarbons; therefore, these solvents cannot be used in oil desulfurization. Ionic liquids have an affinity for acidic gases, making them highly effective at absorbing hydrogen sulfide. However, the high viscosity and low mass transfer efficiency of ionic liquids limit desulfurization efficiency.

[0005] Wet oxidation desulfurization refers to the process where hydrogen sulfide gas is oxidized to elemental sulfur in a liquid-phase desulfurizing agent. It mainly includes iron-based, vanadium-based, and arsenic-based processes. The advantages of iron-based processes over vanadium-based and arsenic-based processes are environmental friendliness and lower cost. However, iron-based processes generate Fe during desulfurization. 3+ To Fe 2+ The changes, conventional iron ion oxidation desulfurization will cause Fe 2+ S 2- It precipitates as FeS, thereby reducing the Fe content. 3+The regenerability of the desulfurizing agent is a concern. Therefore, a complex iron desulfurization method was developed to address this issue. When iron ions and chelating ligands form a chelate, the iron ions are shielded, preventing precipitation after desulfurization and significantly improving the recyclability of the desulfurizing agent. However, iron chelates are typically unstable at high temperatures, making this method unsuitable for high-temperature environments. Furthermore, the low sulfur absorption capacity limits the desulfurization efficiency to some extent.

[0006] Therefore, it is necessary to develop a desulfurizing agent with high sulfur absorption capacity, high desulfurization efficiency, and high temperature resistance. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of low sulfur absorption, low desulfurization efficiency, and poor high-temperature stability in the existing technology, and to provide a desulfurizing agent with high sulfur absorption, high desulfurization efficiency, and high temperature resistance, as well as its preparation method and application, and a high-temperature desulfurization method.

[0008] According to a first aspect of the present invention, the present invention provides a liquid-phase desulfurizing agent comprising: an ionic liquid, a metal chelate, and an aqueous solvent, wherein the metal element comprises Fe.

[0009] According to a second aspect of the present invention, the present invention provides a method for preparing a liquid-phase desulfurizing agent, the method comprising: (1) reacting a chelating agent and a metal salt in the presence of an aqueous solvent under conditions of pH 7-9 to obtain a metal chelate solution; (2) mixing an ionic liquid and a metal chelate solution to obtain a desulfurizing agent, wherein the metal element includes Fe.

[0010] According to a third aspect of the present invention, the present invention provides a liquid-phase desulfurizing agent, which is prepared by the preparation method described in the present invention.

[0011] According to a fourth aspect of the present invention, the present invention provides an application of a liquid-phase desulfurizing agent in high-temperature desulfurization, wherein the liquid-phase desulfurizing agent includes the liquid-phase desulfurizing agent described in the present invention.

[0012] According to a fifth aspect of the present invention, the present invention provides a method for high-temperature desulfurization, the method comprising: contacting and reacting a sulfur-containing gas with a liquid-phase desulfurizing agent, wherein the liquid-phase desulfurizing agent is the liquid-phase desulfurizing agent described in the present invention.

[0013] The liquid-phase desulfurizer provided by this invention has good high-temperature stability and has the advantages of high sulfur absorption and high desulfurization efficiency when applied to desulfurization. Attached Figure Description

[0014] Figure 1 This refers to the change in the mass of the desulfurizing agent sample with temperature during the thermal stability test in Example 1. Figure 2 This refers to the change in the mass of the desulfurizing agent sample with temperature during the thermal stability test in Example 5. Figure 3 This is the change in hydrogen sulfide concentration over time in the outlet gas of the desulfurization reactor during high-temperature desulfurization in Example 1. Detailed Implementation

[0015] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the invention. The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] This invention provides a liquid-phase desulfurizing agent comprising: an ionic liquid, a metal chelate, and an aqueous solvent, wherein the metal element includes Fe. The desulfurizing agent possessing the aforementioned characteristics exhibits high sulfur absorption, high desulfurization efficiency, and good high-temperature stability.

[0017] In this invention, the type of ionic liquid is not particularly limited; any suitable type can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of the invention, the ionic liquid is selected from one or more of 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluorophosphonate. Ionic liquids with the aforementioned characteristics can improve the sulfur absorption capacity, desulfurization efficiency, and high-temperature stability of the desulfurizing agent. Preferably, the ionic liquid is selected from two of 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluorophosphonate, wherein the content of any one ionic liquid is not less than 32 wt% based on the total mass of the ionic liquid. Ionic liquids with the aforementioned preferred characteristics can further improve the high-temperature stability of the desulfurizing agent.

[0018] In the desulfurizing agent described in this invention, the type of metal chelate is not particularly limited; any suitable type can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, the metal chelate is selected from one or more of diethylenetriaminepentaacetic acid metal chelate, ethylenediaminetetramethylenephosphonic acid metal chelate, and hydroxyethylidene diphosphonate metal chelate. Metal chelates with the aforementioned characteristics enable the desulfurizing agent to have higher sulfur absorption capacity, desulfurization efficiency, and high-temperature stability.

[0019] In the desulfurizing agent described in this invention, the ratio of ionic liquid to metal chelate can be selected within a wide range. The following is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the mass ratio of ionic liquid to metal chelate, calculated by metal element, is 30-65:1. For example, it can be 35:1, 40:1, 45:1, 50:1, 55:1, or 60:1.

[0020] In the desulfurizing agent described in this invention, the content ratio of metal chelate to water solvent can be selected within a wide range. The following is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the content ratio of the metal chelate to water solvent, calculated as metal element, is 0.03-0.1 g:10 mL. For example, it can be 0.04 g:10 mL, 0.05 g:10 mL, 0.06 g:10 mL, 0.07 g:10 mL, 0.08 g:10 mL, or 0.09 g:10 mL.

[0021] According to a preferred embodiment of the present invention, the desulfurizing agent of the present invention further includes Mn and / or Co as metal elements.

[0022] In the desulfurizing agent described in this invention, the content of Mn in the metal chelate has a wide range of selectable values. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of Mn to Fe in the metal chelate, based on elemental composition, is 10-20:1. For example, it can be 12:1, 14:1, 16:1, or 18:1.

[0023] In the desulfurizing agent described in this invention, the content of Co in the metal chelate has a wide range of selectable values. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of Co to Fe in the metal chelate, based on elemental composition, is 5-10:1. For example, it can be 6:1, 7:1, 8:1, or 9:1.

[0024] This invention does not have special requirements for the preparation method of the liquid-phase desulfurizing agent. As long as a liquid-phase desulfurizing agent that meets the aforementioned requirements can be prepared, the purpose of this invention can be achieved. According to a preferred embodiment of this invention, this invention provides a method for preparing a liquid-phase desulfurizing agent, which includes: (1) reacting a chelating agent and a metal salt in the presence of an aqueous solvent under conditions of pH 7-9 to obtain a metal chelate solution; (2) mixing an ionic liquid and a metal chelate solution to obtain a desulfurizing agent, wherein the metal element includes Fe. The preparation method with the aforementioned characteristics can easily prepare a desulfurizing agent with high sulfur absorption, high desulfurization efficiency, and high temperature resistance.

[0025] In the preparation method described in this invention, the type of chelating agent is not particularly limited; any suitable type can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, the chelating agent is selected from one or more of diethylenetriaminepentaacetic acid, ethylenediaminetetramethylenephosphonic acid, and hydroxyethylidene diphosphonate. Chelating agents with the aforementioned characteristics enable the desulfurizing agent to have higher sulfur absorption capacity, desulfurization efficiency, and high-temperature stability.

[0026] In the preparation method described in this invention, the type of metal salt is not particularly limited; any suitable type can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, the metal salt is selected from one or more salts of metals, such as nitrates and nitrate hydrates.

[0027] Those skilled in the art will understand that in the preparation method described in this invention, in step (1), "the condition with a pH value of 7-9" refers to the pH value at 25°C.

[0028] In the preparation method described in this invention, the pH condition in step (1) can be achieved by using a pH adjuster. There is no particular limitation on the type of pH adjuster; any suitable type can be selected as long as it achieves the purpose of this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the pH adjuster is an alkali metal hydroxide. For example, it can be NaOH.

[0029] In the preparation method described in this invention, the method of providing the pH adjuster in step (1) is not particularly limited. Any suitable method can be selected as long as it can achieve the purpose of this invention. The following is an illustrative description, but it does not limit the scope of this invention. For example, it can be provided in the form of an aqueous solution of pH adjuster with a concentration of 5-15 wt%.

[0030] In the preparation method described in this invention, the ratio of chelating agent to metal salt in step (1) can be selected within a wide range. The following is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of chelating agent to metal salt, calculated as metal element, is 8-20:1. For example, it can be 10:1, 12:1, 14:1, 16:1, or 18:1.

[0031] In the preparation method described in this invention, the ratio of chelating agent to aqueous solvent in step (1) can be selected within a wide range. The following is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the ratio of chelating agent to aqueous solvent is 0.1-1.5 g:10 mL. For example, it can be 0.3 g:10 mL, 0.5 g:10 mL, 0.7 g:10 mL, 0.9 g:10 mL, 1.1 g:10 mL, or 1.3 g:10 mL.

[0032] In the preparation method described in this invention, in step (1), as is known to those skilled in the art, in order to fully dissolve the chelating agent in the aqueous solvent, the chelating agent can be added to the aqueous solvent first, and the temperature can be raised to, for example, 60°C, so that the chelating agent can be fully dissolved, and then the metal salt can be added to react with the chelating agent at the reaction temperature.

[0033] In the preparation method described in this invention, the ratio of ionic liquid to metal chelate in step (2) can be selected within a wide range. The following is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of ionic liquid to metal chelate, calculated by metal element, is 30-65:1. For example, it can be 35:1, 40:1, 45:1, 50:1, 55:1, or 60:1.

[0034] In the preparation method described in this invention, in step (2), as is known to those skilled in the art, the mixing can be carried out under dynamic conditions in order to fully mix the ionic liquid and the metal chelate solution.

[0035] According to a preferred embodiment of the present invention, the preparation method further includes: concentrating the metal chelate solution.

[0036] In the preparation method described in this invention, the concentration time can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of the invention, the concentration is carried out until the concentration of the metal chelate, calculated as metal element, is 0.03-0.1 g / 10 mL. For example, it can be 0.04 g:10 mL, 0.05 g:10 mL, 0.06 g:10 mL, 0.07 g:10 mL, 0.08 g:10 mL, or 0.09 g:10 mL.

[0037] In the preparation method described in this invention, the concentration method is not particularly limited; any suitable method can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, the concentration is achieved by oil bath evaporation concentration.

[0038] In the preparation method described in this invention, the temperature range for oil bath evaporation and concentration is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the temperature for oil bath evaporation and concentration is 65-90°C.

[0039] According to a preferred embodiment of the present invention, the metal element in the preparation method of the present invention further includes Mn and / or Co.

[0040] In the preparation method described in this invention, the amount of Mn metal salt can be selected from a wide range. The following is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of Mn metal salt to Fe metal salt, based on the metal element, is 10-20:1. For example, it can be 12:1, 14:1, 16:1, or 18:1.

[0041] In the preparation method described in this invention, the amount of Co metal salt can be selected from a wide range. The following is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of Co metal salt to Fe metal salt, based on metal elements, is 5-10:1. For example, it can be 6:1, 7:1, 8:1, or 9:1.

[0042] In the preparation method described in this invention, the temperature range for the contact reaction is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the temperature of the contact reaction is 25-40°C.

[0043] In the preparation method described in this invention, the contact reaction time can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the contact reaction time is 8-16 hours.

[0044] In the preparation method described in this invention, as is known to those skilled in the art, the contact reaction can be carried out under dynamic conditions to ensure its full and uniformity. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the stirring speed of the contact reaction is 400-800 rpm.

[0045] This invention provides a liquid-phase desulfurizing agent, which is prepared by the preparation method described in this invention.

[0046] The liquid-phase desulfurizing agent described in this invention is particularly suitable for use in high-temperature desulfurization.

[0047] In the applications described in this invention, the temperature range for high-temperature desulfurization is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of the invention, the temperature for high-temperature desulfurization is 60-150°C.

[0048] This invention provides a method for high-temperature desulfurization, the method comprising: contacting sulfur-containing gas with a liquid-phase desulfurizing agent for reaction, wherein the liquid-phase desulfurizing agent is the liquid-phase desulfurizing agent described in this invention.

[0049] In the high-temperature desulfurization method described in this invention, the content of sulfur-containing compounds in the sulfur-containing gas can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the content of sulfur-containing compounds in the sulfur-containing gas is 100-5000 ppm.

[0050] In the high-temperature desulfurization method described in this invention, the types of sulfur-containing compounds in the sulfur-containing gas are not particularly limited; any suitable type can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, the sulfur-containing compounds in the sulfur-containing gas are hydrogen sulfide and / or gaseous organic sulfides.

[0051] In the high-temperature desulfurization method of this invention, the type of main gas in the sulfur-containing gas is not particularly limited; any suitable type can be selected as long as it achieves the purpose of this invention. According to a preferred embodiment of this invention, the main gas in the sulfur-containing gas is selected from one or more of nitrogen, air, water vapor, and sulfur-free organic gases.

[0052] In the high-temperature desulfurization method described in this invention, the temperature range for the contact reaction is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of the invention, the temperature of the contact reaction is 60-150°C.

[0053] In the high-temperature desulfurization method described in this invention, the range of selectable gas velocities in the empty tower of the contact reaction is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the gas velocity in the empty tower of the contact reaction is 0.01-0.1 m / s, preferably 0.01-0.05 m / s.

[0054] The present invention will be described in detail below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0055] In the examples and comparative examples Thermal stability was tested by thermogravimetric analysis: the desulfurizer was placed in the thermogravimetric analyzer, the heating program was set and the temperature was raised to 500℃ and then stopped. The change in sample mass with temperature was recorded. m% = remaining mass of sample after test m2 / mass of sample before test m1 × 100%. The larger the value of m%, the better the thermal stability of the desulfurizer.

[0056] Example 1 1.5 g of diethylenetriaminepentaacetic acid was dissolved in 60 mL of water at 60 °C, and the pH was adjusted to 8 using a 10 wt% NaOH aqueous solution. 0.615 g of ferric nitrate nonahydrate, 0.035 g of 50 wt% manganese nitrate solution, and 0.051 g of cobalt nitrate hexahydrate were added, and the reaction was carried out at 30 °C and 500 rpm for 12 h with stirring. The resulting product was then evaporated and concentrated to 20 mL in an 80 °C oil bath to obtain 22.184 g of a diethylenetriaminepentaacetic acid metal chelate solution.

[0057] Add 3.63 g of 1-butyl-3-methylimidazolium bromide to the metal chelate solution, shake to dissolve and obtain the desulfurizing agent.

[0058] The obtained desulfurizing agent was used for high-temperature desulfurization. The high-temperature desulfurization method was as follows: the desulfurizing agent was placed in a desulfurization reactor, and a gas containing hydrogen sulfide (hydrogen sulfide concentration of 1000 ppm, with the remainder being nitrogen) was continuously introduced into the reactor to carry out the desulfurization reaction. The reaction temperature was 95℃, and the empty tower gas velocity was 0.02 m / s. The hydrogen sulfide concentration of the gas exiting the desulfurization reactor was continuously monitored, and the detection results were as follows: Figure 3 As shown, the hydrogen sulfide concentration in the outlet gas was 0 ppm when the reaction proceeded for 0.5 h; and the hydrogen sulfide concentration in the outlet gas was 0 ppm when the reaction proceeded for 4 h.

[0059] Thermal stability testing was conducted, and the sample mass changed with temperature as follows: Figure 1 As shown, m% is 8.6%.

[0060] Example 2 1.5 g of ethylenediaminetetramethylenephosphonic acid was dissolved in 60 mL of water at 60 °C, and the pH was adjusted to 8 using a 10 wt% NaOH aqueous solution. 0.561 g of ferric nitrate nonahydrate, 0.042 g of 50 wt% manganese nitrate solution, and 0.047 g of cobalt nitrate hexahydrate were added, and the reaction was carried out at 30 °C and 500 rpm for 12 h with stirring. The resulting product was then evaporated and concentrated to 20 mL in an 80 °C oil bath to obtain 22.129 g of a diethylenetriaminepentaacetic acid metal chelate solution.

[0061] Add 3.276 g of 1-butyl-3-methylimidazolium bromide to the metal chelate solution, shake to dissolve and obtain the desulfurizing agent.

[0062] The obtained desulfurizing agent was used for high-temperature desulfurization. The high-temperature desulfurization method was as follows: the desulfurizing agent was placed in a desulfurization reactor, and a gas containing hydrogen sulfide (hydrogen sulfide concentration of 1000 ppm, with the remainder being nitrogen) was continuously introduced into the reactor to carry out the desulfurization reaction. The reaction temperature was 95℃, and the empty tower gas velocity was 0.02 m / s. The hydrogen sulfide concentration of the outlet gas of the desulfurization reactor was continuously monitored. After 0.5 hours of reaction, the hydrogen sulfide concentration of the outlet gas was 0 ppm; after 4 hours of reaction, the hydrogen sulfide concentration of the outlet gas was also 0 ppm.

[0063] Thermal stability tests were conducted, and m% was 8.5%.

[0064] Example 3 1.5 g of tetrasodium hydroxyethylidene bisphosphonate was dissolved in 60 mL of water at 60 °C. Then, 0.833 g of ferric nitrate nonahydrate, 0.064 g of 50 wt% manganese nitrate solution, and 0.069 g of cobalt nitrate hexahydrate were added. The reaction mixture was reacted at 30 °C and 500 rpm for 12 h with stirring. The resulting product was then evaporated and concentrated to 20 mL in an 80 °C oil bath to obtain 22.434 g of a tetrasodium hydroxyethylidene bisphosphonate metal chelate solution.

[0065] Add 4.86 g of 1-butyl-3-methylimidazolium bromide to the metal chelate solution, shake to dissolve and obtain the desulfurizing agent.

[0066] The obtained desulfurizing agent was used for high-temperature desulfurization. The high-temperature desulfurization method was as follows: the desulfurizing agent was placed in a desulfurization reactor, and a gas containing hydrogen sulfide (hydrogen sulfide concentration of 1000 ppm, with the remainder being nitrogen) was continuously introduced into the reactor to carry out the desulfurization reaction. The reaction temperature was 95℃, and the empty tower gas velocity was 0.02 m / s. The hydrogen sulfide concentration of the outlet gas of the desulfurization reactor was continuously monitored. After 0.5 hours of reaction, the hydrogen sulfide concentration of the outlet gas was 0 ppm; after 4 hours of reaction, the hydrogen sulfide concentration of the outlet gas was also 0 ppm.

[0067] Thermal stability tests were conducted, and the m% value was 8.6%.

[0068] Example 4 Following the method of Example 1, except that 5.55 g of 1-butyl-3-methylimidazolium bromide was added to 22.184 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing showed a m% of 9.1%.

[0069] Example 5 Following the method of Example 1, except that 3.63 g of 1-ethyl-3-methylimidazolium bromide was added to 22.184 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing was performed, and the sample mass changed with temperature as follows: Figure 2 As shown, m% is 10.1%.

[0070] Example 6 Following the method of Example 1, except that 3.63 g of 1-butyl-3-methylimidazolium tetrafluorophosphonate was added to 22.184 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing showed a m% of 9.7%.

[0071] Example 7 Following the method of Example 2, except that 5.53 g of 1-butyl-3-methylimidazolium bromide was added to 22.129 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing showed a m% of 9.1%.

[0072] Example 8 Following the method of Example 2, except that 3.276 g of 1-ethyl-3-methylimidazolium bromide was added to 22.129 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing was performed, and the m% value was 10.0%.

[0073] Example 9 Following the method of Example 2, except that 3.276 g of 1-butyl-3-methylimidazolium tetrafluorophosphonate was added to 22.129 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing showed a m% of 9.8%.

[0074] Example 10 Following the method of Example 1, except that 2.42 g of 1-butyl-3-methylimidazolium bromide was added to 22.184 g of the metal chelate solution, and the solution was dissolved by shaking to obtain the desulfurizing agent. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was 167 ppm. Thermal stability testing showed a m% of 6.3%.

[0075] Example 11 The method was followed as in Example 1, except that no concentration was performed when preparing the metal chelate solution. After 0.5 hours of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 73 ppm; after 4 hours of reaction, the hydrogen sulfide concentration in the outlet gas was 81 ppm. Thermal stability testing showed a m% of 8.4%.

[0076] Example 12 The method was followed in Example 1, except that manganese nitrate solution was not added, and the amount of ferric nitrate nonahydrate added was 0.652 g. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 16 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was 54 ppm. Thermal stability testing showed a m% of 7.6%.

[0077] Example 13 The method was followed in Example 1, except that cobalt nitrate hexahydrate was not added, and ferric nitrate nonahydrate was added in an amount of 0.688 g. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 21 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was 62 ppm. Thermal stability testing showed a m% of 7.4%.

[0078] Example 14 The method was followed in Example 3, except that the amount of tetrasodium hydroxyethylidene diphosphonate added was 1g. After 0.5 hours of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 hours of reaction, the hydrogen sulfide concentration in the outlet gas was 132 ppm. Thermal stability testing showed a m% of 6.5%.

[0079] Example 15 The method was followed as in Example 1, except that 3.63 g of 1-butyl-3-methylimidazolium bromide was replaced with 1.815 g of both 1-butyl-3-methylimidazolium bromide and 1.815 g of 1-butyl-3-methylimidazolium tetrafluorophosphonate. After 0.5 h of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 0 ppm; after 4 h of reaction, the hydrogen sulfide concentration in the outlet gas was also 0 ppm. Thermal stability testing showed a m% of 11.6%.

[0080] Comparative Example 1 The method was followed in Example 1, except that no ionic liquid was added to the metal chelate solution; instead, the metal chelate solution was used directly as the desulfurizing agent. After 0.5 hours of high-temperature desulfurization reaction, the hydrogen sulfide concentration in the outlet gas was 219 ppm; after 4 hours of reaction, the hydrogen sulfide concentration in the outlet gas was 970 ppm. Thermal stability testing showed a m% of 4.2%.

[0081] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A liquid-phase desulfurizing agent, characterized in that, The desulfurizing agent comprises: ionic liquid, metal chelate, and water solvent, wherein the metal element includes Fe.

2. The desulfurizing agent according to claim 1, characterized in that, The ionic liquid is selected from one or more of 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluorophosphonate.

3. The desulfurizing agent according to claim 1, characterized in that, The ionic liquid is selected from two of 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluorophosphonate, wherein the content of any one ionic liquid is not less than 32 wt% based on the total mass of the ionic liquid.

4. The desulfurizing agent according to claim 1, characterized in that, The metal chelate is selected from one or more of diethylenetriaminepentaacetic acid metal chelate, ethylenediaminetetramethylenephosphonic acid metal chelate, and hydroxyethylidene diphosphonate metal chelate.

5. The desulfurizing agent according to claim 1, characterized in that, Metal chelates, calculated as metal elements, The mass ratio of ionic liquid to metal chelate is 30-65:1; and / or The ratio of metal chelate to water solvent is 0.03-0.1 g: 10 mL.

6. The desulfurizing agent according to any one of claims 1-5, characterized in that, Metallic elements also include Mn and / or Co.

7. The desulfurizing agent according to claim 6, characterized in that, In metal chelates, on an elemental basis, The mass ratio of Mn to Fe is 10-20:1; and / or The mass ratio of Co to Fe is 5-10:

1.

8. A method for preparing a liquid-phase desulfurizing agent, characterized in that, The method includes: (1) Under conditions of pH 7-9, in the presence of an aqueous solvent, the chelating agent and the metal salt are reacted to obtain a metal chelate solution; (2) The ionic liquid and the metal chelate solution are mixed to obtain a desulfurizing agent. Among them, metallic elements include Fe.

9. The preparation method according to claim 8, characterized in that, The ionic liquid is selected from one or more of 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluorophosphonate; and / or The chelating agent is selected from one or more of diethylenetriaminepentaacetic acid, ethylenediaminetetramethylenephosphonic acid, and hydroxyethylidene diphosphonate; and / or The metal salt is selected from one or more of the following: metal nitrates, nitrate hydrates; and / or The pH adjuster is an alkali metal hydroxide.

10. The desulfurizing agent according to claim 9, characterized in that, The ionic liquid is selected from two of 1-butyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, and 1-butyl-3-methylimidazolium tetrafluorophosphonate, wherein the amount of any one ionic liquid is not less than 32 wt% based on the total mass of the ionic liquid.

11. The preparation method according to claim 8, characterized in that, In step (1), The mass ratio of chelating agent to metal salt, calculated based on the metal element, is 8-20:1; and / or The ratio of chelating agent to water solvent is 0.1-1.5g:10mL.

12. The preparation method according to claim 8, characterized in that, In step (2), the mass ratio of the ionic liquid to the metal chelate is 30-65:1, calculated by metal element.

13. The preparation method according to claim 8, characterized in that, The method further includes concentrating the metal chelate solution to a concentration of 0.03-0.1 g / 10 mL based on the metal element.

14. The preparation method according to any one of claims 8-13, characterized in that, Metallic elements also include Mn and / or Co.

15. The preparation method according to claim 14, characterized in that, In terms of metallic elements, The mass ratio of Mn metal salt to Fe metal salt is 10-20:1; and / or The mass ratio of Co metal salt to Fe metal salt is 5-10:

1.

16. The preparation method according to claim 8, characterized in that, The conditions for a contact reaction include: Temperature is 25-40℃; and / or The time is 8-16 hours.

17. A liquid-phase desulfurizing agent, characterized in that, The desulfurizing agent is prepared by the preparation method described in any one of claims 8-16.

18. The application of a liquid-phase desulfurizing agent in high-temperature desulfurization, characterized in that, The liquid phase desulfurizer includes the liquid phase desulfurizer described in any one of claims 1-7 and 17.

19. The application according to claim 18, characterized in that, The temperature for high-temperature desulfurization is 60-150℃.

20. A method for high-temperature desulfurization, the method comprising: The sulfur-containing gas is reacted with a liquid-phase desulfurizing agent, characterized in that the liquid-phase desulfurizing agent is the liquid-phase desulfurizing agent described in any one of claims 1-7 and 17.

21. The method according to claim 20, characterized in that, In sulfur-containing gases, The content of sulfur-containing compounds is 100-5000 ppm; and / or Sulfur-containing compounds are hydrogen sulfide and / or gaseous organic sulfides; and / or The main gas is selected from one or more of nitrogen, air, water vapor, and sulfur-free organic gases; and / or The conditions for a contact reaction include: The temperature is 60-150℃; and / or The air velocity in the empty tower is 0.01-0.1 m / s.

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